Field of the Invention
The present invention relates to novel protease variants exhibiting alterations relative to the parent protease in one or more properties including: wash performance, detergent stability and/or storage stability. The variants of the invention are suitable for use in cleaning processes and detergent compositions, such as laundry compositions and dish wash compositions, including hand wash and automatic dish wash compositions. The present invention also relates to isolated DNA sequences encoding the variants, expression vectors, host cells, and methods for producing and using the protease variants of the invention.
Description of the Related Art
Enzymes have been used within the detergent industry as part of washing formulations for many decades. Proteases are from a commercial perspective the most relevant enzyme in such formulations, but other enzymes including lipases, amylases, cellulases, hemicellulases or mixtures of enzymes are also often used. To improve the cost and/or the performance of proteases there is an ongoing search for proteases with altered properties, such as increased activity at low temperatures, increased stability, increased specific activity at a given pH, altered Ca2+ dependency, increased stability in the presence of other detergent ingredients (e.g. bleach, surfactants etc.) etc. One family of proteases, which are widely used in detergents, are the subtilases. This family has previously been further grouped into 6 different sub-groups by Siezen R J and Leunissen J A M, 1997, Protein Science, 6, 501-523. One of these sub-groups is the Subtilisin family which includes subtilases such as BPN′, subtilisin 309 (SAVINASE®, Novozymes A/S), subtilisin Carlsberg (ALCALASE®, Novozymes A/S), subtilisin S41 (a subtilase from the psychrophilic Antarctic Bacillus TA41, Davail S et al. 1994, The Journal of Biological Chemistry, 269(26), 99. 17448-17453) and subtilisin S39 (a subtilase from the psychrophilic Antarctic Bacillus TA39, Narinx E et al. 1997, Protein Engineering, 10 (11), pp. 1271-1279). The TY-145 protease is a subtilase from Bacillus sp. TY-145, NCIMB 40339, which was first described in WO 92/17577 (Novozymes A/S) and in the later application WO2004/067737 (Novozymes A/S) disclosing the three-dimensional structure and the use of protein engineering to alter functionality of a TY-145 subtilase.